Field of the Invention
Our invention relates to plastic bags and blown film processes for making plastic bags. In specific examples, our invention relates to a roll of plastic bags that is made in a tubular blown film process, with the roll of plastic bags including perforations to separate bags from the roll such that the edges of the bags formed along the perforations facilitate opening of the bags.
Related Art
Bags made from flexible plastic materials are well known. Such plastic bags are made in a variety of sizes, and can be used to contain a variety of items, including food, utensils, clothing, tools, etc. For some applications, a roll of joined plastic bags is formed, with the roll including perforations to allow individual bags to be torn away from the rest of the roll. Rolls of plastic bags are provided, for example, in the produce section of a supermarket, where a consumer separates a bag from the roll and then fills the separated bag with the fruits or vegetables for purchase. As another example, a roll of plastic bags is sometimes provided in a compact package, with a user separating an individual bag from the roll in the package. Plastic garbage bags, for example, are sometimes provided in such a roll and compact package.
There are different manufacturing processes used to make plastic bags. In one type of such process, a tubular blown film is first formed and then processed into a roll of unseparated “tube bags.” In blown film processes, the tubular blown film is first collapsed, perforations for later separation of the bags are formed in the collapsed tubular blown film, and then the collapsed, perforated film is wound into a roll.
To open a plastic storage bag separated from a roll, the user grasps the lips of the bag that are adjacent to the end with the opening, and then the user pulls the lips in opposite directions to open the opening. Plastic bags often have slick surfaces, however, that are difficult to grasp. Moreover, depending on the type of plastic used to manufacture a given bag, opposite sides of the bag may stick together, thereby making it even more difficult to open the bag. Still further, it is sometimes difficult for a user to distinguish between the end of the bag with the opening and the opposite, permanently sealed end of the bag.
It would be beneficial, therefore, to provide a roll of plastic bags such that, when the bags are separated from the roll, users can easily open the bags. Further, it would be beneficial if such a roll of plastic bags could be manufactured using a blown tubular film process.